A South African police forensics analyst has testified that Oscar Pistorius was likely not wearing his prosthetic legs when he used a cricket bat to hit the door through which he fatally shot his girlfriend last year.

The door was set up in court Wednesday as Johannes Vermeulen described how marks on the bat matched up with two holes in the door, saying it is indisputable they were caused by the bat.

He demonstrated the angles that his analysis showed were used, and said the marks were not consistent with Pistorius wearing his prosthetics.

Pistorius said in an affidavit during an earlier bail hearing that he had put on the prosthetics prior to hitting the door with a cricket bat.

His lawyer, in cross-examining Vermeulen, said the defense team can show the same marks can be made from someone in a standing position.

Prosecutors accuse Pistorius of murdering Steenkamp after an argument, while he says says he thought he was shooting at an intruder.

The runner has pleaded not guilty to charges of murder, recklessly discharging a firearm and illegally possessing ammunition.

If convicted of premeditated murder, he faces a life sentence.

Pistorius is known as the "Blade Runner" for his carbon-fiber prosthetic legs. In 2012, he became the first double-amputee to compete in the Olympics.